Elongate light block assembly lamp

ABSTRACT

An electrically operated lamp that includes an elongate, transparent envelope having two tubular legs extending outwardly in the same direction from the ends thereof, the legs being substantially normal to the longitudinal axis of the envelope. At least one elongate refractory element that may be brought to incandescence by passage of an electric current therethrough is longitudinally disposed within the envelope and is at all times maintained in tension by two electric current-conducting springs at least partially housed within the legs. The lamp is particularly adapted for use with light block assemblies to produce an elongate zone of illumination of substantially uniform intensity through which multiple channel punched cards or punched tape pass. A light from this zone passes through openings in the cards or tape to actuate a lightsensitive receptor. The possibility of one or more channels of coding or decoding being lost due to individual lamp failures is eliminated, when a lamp of the present invention is used as a source for the zone of uniform light intensity. This zone extends transversely across the punched card or tape as the card or tape moves through a predetermined position.

ilnited States stem 1191 Carley June 12, 1973 ELONGATE LIGHT BLOCK ASSEMBLY LAMP [75] Inventor:

James A. Carley, Rolling Hills, Calif.

Los Angeles Miniature Products, Inc., Torrance, Calif.

Sept. 24, 1971 Assignee:

Filed:

Appl. No.:

References Cited UNITED STATES PATENTS 10/1970 Notelteirs et al. 313/274 X 4/l9ll Welsh 313/274 7/1910 OBrien 313/278 X l0/l9l2 Knowles 313/278 X Primary ExaminerJohn K. Corbin Att0rneyWilliam C. Babcock [57] ABSTRACT An electrically operated lamp that includes an elongate, transparent envelope having two tubular legs ex tending outwardly in the same direction from the ends thereof, the legs being substantially normal to the longitudinal axis of the envelope. At least one elongate refractory element that may be brought to incandescence by passage of an electric current therethrough is longitudinally disposed within the envelope and is at all times maintained in tension by two electric currentconducting springs at least partially housed within the legs.

The lamp is particularly adapted for use with light block assemblies to produce an elongate zone of illumination of substantially uniform intensity through which multiple channel punched cards or punched tape pass. A light from this zone passes through openings in the cards or tape to actuate a light-sensitive receptor.

The possibility of one or more channels of coding or decoding being lost due to individual lamp failures is eliminated, when a lamp of the present invention is used as a source for the zone of uniform light intensity. This zone extends transversely across the punched card or tape as the card or tape moves through a predetermined position.

2 Claims, 6 Drawing Figures Patented June 12, 1973 3,739,219

INVENTOR. elk/was A, @fiQLY ELONGATE LIGHT BLOCK ASSEMBLY LAMP BACKGROUND OF THE INVENTION 1. Field of the Invention Light block assembly lamp.

2. Description of the prior art In the past, it has been common practice to move opaque, multiple channel, punched cards or tape longitudinally between a source of light and a light-sensitive receptor to decode message on the cards or tape. The source of light for such an operation in the past has frequently been a number of individual electrically operated lamps. Each such lamp has its individual lightemitting characteristic, and to make the light-emission characteristic of the individual lamps uniform, even when the lamps are operated on the same voltage, each lamp has to be provided with its own individual trim resistor.

The use of multiple lamps with individual resistors results in excessive wiring, as well as the waste of valuable time in adjusting the resistors so that all of the lamps emit light of substantially the same intensity.

A further disadvantage of multiple lamps as a source of light for coding and decoding operations is that one of the lamps may fail, resulting in improper operation of the machine that is controlled by punched cards or punched tape.

Various efforts have been made in the past to provide a single lamp that will overcome the operational disadvantages of multiple lamps as a source of a uniform light field or zone. The individual lamps so produced have, in turn, had the operational disadvantages that they are unduly bulky and cumbersome, and are limited in wattage consumption to the current a resilient spring used in tensioning the incandescent element will conduct before the spring anneals and becomes useless for its intended purpose.

The primary purpose in devising the present electrically operated lamp is to provide a lamp that is simple in structure, compact, and one that is substantially free of the operational disadvantages of prior art devices of this nature.

SUMMARY OF THE INVENTION An electrically operated lamp for use in providing an elongate zone of light of substantially uniform intensity, with the lamp including an elongate, transparent, tubular envelope that has first and second tubular sealed legs projecting outwardly from the first and second ends thereof. The first and second legs project outwardly from the envelope in the same direction, and preferably are substantially normal to the longitudinal axis of the envelope. At least one elongate electrical resistance element, formed ofa refractory metal that may be brought to incandescence by passage of an electric current therethrough, is situated longitudinally within the elongate envelope, with the element being maintained in tension at all times, both when cold and when heated, by two electrical conducting resilient springs that are at least partially disposed within the tubular legs.

A major object of the present invention is to provide a single, electrically operated lamp that furnishes an elongate, illuminated zone of substantially uniform intensity, and eliminates the necessity of trimming resistors that are required when multiple lamps are used for this purpose.

Another object of the invention is to supply a single lamp that is of less transverse cross section and overall length than prior art devices of this nature, and a lamp that upon failure thereof stops the machine that is controlled by the punched cards or tape, rather than permitting the machine to continue to operate with spurious coding being generated, as occurs when multiple lamps are used.

A further object of the invention is to provide a single lamp that will furnish an illuminated zone of the same size and magnitude as that achieved by multiple lamp installations, but with the wiring and cost being substantially reduced over that involved when a number of lamps are used to provide the lighted zone.

Another object of the invention is to supply a lamp that may either plug in or clip on to a suitable source of power to supply an elongate illuminated zone, and a lamp that is more resistant to shock and vibration than prior art lamps of this nature.

Yet another object of the invention is to furnish an electrically operated lamp having an elongate, transparent envelope through which a refractory metal element extends that may be heated to incandescence, with the element being so spring-supported that it may expand and contract as it heats and cools without sagging, and with the springs so supporting the element being of such structure that they may be subjected to a relatively heavy electric current without heating and annealing to the extent that they no longer serve their intended purpose.

DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of the lamp that is particularly adapted for providing an elongate, illuminated field of substantially uniform light intensity, such as is required in the operation of a light block assembly through which punched cards or punched tape pass;

FIG. 2 is a longitudinal, cross-sectional view of the lamp shown in FIG. 1 taken on the line 2-2 thereof;

FIG. 3 is a longitudinal, cross-sectional view of the lamp taken on the line 33 of FIG. 2;

FIG. 4 is the same longitudinal, cross-sectional view of the Iamp shown in FIG. 2, but modified to have a plurality of parallel, laterally spaced filaments extending between the springs that project downwardly in the legs of the lamp;

FIG. 5 is a transverse, cross-sectional view of the modified form of lamp shown in FIG. 4, taken on the line 5-5 thereof; and

FIG. 6 is a perspective view of a light block assembly utilizing the lamp shown in FIG. 1, with a punched tape being disposed between the light-sensitive receptor and the lamp.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The first form A of the lamp, as may best be seen in FIG. 1, includes an elongate, transparent tubular envelope 10 which develops on its ends into first and second tubular legs 12 and 12 that extend outwardly from the envelope and are substantially normal to the longitudinal axis thereof. The first and second tubular legs 12 and 12 have first and second outwardly disposed sealed ends 14 and 14.

First and second electrical conductors 16 and 16' are provided that extend through the first and second ends 14 and 14', and are sealed to the ends by being fused thereto. The conductors 16 and 16' have end portions situated within the confines of the legs 12 and 12'. Elongate first and second electrical conducting springs 18 and 18 are situated within the confines of the tubular legs 12 and 12, and by welding beads 20 and 20 are secured to the electrical conductors l6 and 16'.

An elongate resistance element 21, preferably in the form of a ribbon, is provided that is defined by a refractory metal or alloy that may be brought to incandescence when an electric current is caused to flow therethrough. The resistance element 21 is slightly shorter than the distance between the first and second springs 18 and 18. By welding beads 22 and 22 the ends of the resistance element 21 are secured to the springs 18 and 18, and deform the springs to a slight degree towards one another to maintain tension on the resistance element 21. The deformation of the springs 18 and 18' is sufficient to maintain the resistance element 21 taut when the metal defining the same expands as the resistance element is brought to incandescence by passage of an electric current therethrough.

A light block assembly is shown diagrammatically in FIG. 6 that includes a punched tape B that is exposed to an elongate transverse zone of light from the lamp A as it passes thereunder. Beams of light C may pass from the illuminated zone downwardly through openings 23 in the punched tape B to impinge on lightsensitive areas 24 formed in a receptor block D. The receptor block is electrically associated by means (not shown) that are conventional to operate a machine or perform other operations in accordance with the coded multi-channeled openings on the tape B. Of course, it will be apparent that punched cards (not shown) may be used in lieu of the punched tape B if desired.

A modification of the lamp A which is shown in FIGS. 4 and and identified by the letter A is adapted to provide the same operational advantages as the first described form A of the lamp. The lamp A has first and second springs 18 and 18 therein that terminate on their lower ends in laterally spaced teeth 26, with the teeth having a number of parallel, laterally spaced filaments 28 secured thereto by welding or the like. The filaments 28 are held in a taut condition by the springs 18 and 18' in the same manner as the ribbonlike resistance element 21.

The filaments 28 are preferably formed from a refractory metallic material such as tungsten. The advantage of the filaments 28 over the ribbon-like resistance element 21 is that the filaments may be operated at a higher voltage with a lowerelectrical current draw than the element 21. However, the filaments 28 do have the operational disadvantage that they are less resistant to shock and vibration than the ribbon-like resistance element 21. Both the first form A and the second form A of the electrically operated lamp are adapted to perform the same function, and operate to produce an elongate zone oflight of substantially uniform intensity.

The electrical conductors 16 and 16' project outwardly sufficiently from the legs 12 and 12 to the extent that they may be inserted into a suitable electrical outlet fixture (not shown), or clipped to a source of electrical energy.

The use and operation of the invention has been previously described in detail and need not be repeated.

I claim:

1. An electrically operated light block assembly lamp for use in providing an elongate zone of light of substantially uniform intensity, said lamp including:

a. an elongate transparent tubular envelope that has first and second ends;

b. first and second tubular legs connected to said first and second ends and extending outwardly therefrom substantially normal to the longitudinal axis of said envelope, said first and second legs having first and second sealed free ends;

c. first and second electrical conductors sealingly mounted in said first and second ends and with first sections of said conductors extending into said first and second legs;

d. a plurality of elongate electrical resistance elements in the form of filaments that are longitudinally disposed in said envelope that may be heated to incandescence by the flow of an electric current therethrough; and

e. first and second electrical conducting springs, each having first and second ends, said springs at least partially disposed within said first and second legs, said first ends of said first and second springs bonded to said first ends of said sections, with said second ends of said springs in the form of a plurality of teeth that are bonded to opposite ends of said resistance elements, and said springs so spaced that said resistance elements are maintained in tension both when cold and when heated.

2. A lamp as defined in claim 1 in which said resistance elements are parallel and laterally spaced from one another. 

1. An electrically operated light block assembly lamp for use in providing an elongate zone of light of substantially uniform intensity, said lamp including: a. an elongate transparent tubular envelope that has first and second ends; b. first and second tubular legs connected to said first and second ends and eXtending outwardly therefrom substantially normal to the longitudinal axis of said envelope, said first and second legs having first and second sealed free ends; c. first and second electrical conductors sealingly mounted in said first and second ends and with first sections of said conductors extending into said first and second legs; d. a plurality of elongate electrical resistance elements in the form of filaments that are longitudinally disposed in said envelope that may be heated to incandescence by the flow of an electric current therethrough; and e. first and second electrical conducting springs, each having first and second ends, said springs at least partially disposed within said first and second legs, said first ends of said first and second springs bonded to said first ends of said sections, with said second ends of said springs in the form of a plurality of teeth that are bonded to opposite ends of said resistance elements, and said springs so spaced that said resistance elements are maintained in tension both when cold and when heated.
 2. A lamp as defined in claim 1 in which said resistance elements are parallel and laterally spaced from one another. 